Groundwater Flood Risk

Groundwater Flood Risk Map at 5m Resolution

To give insurers, developers and property asset managers an even more comprehensive overview of flood risk, Ambiental has partnered with GeoSmart to provide the most precise groundwater flooding dataset available in the UK today.

Groundwater flooding is often overlooked when it comes to assessing flood risk, even though it causes two to four times more damage to property than surface flooding events.  It may occur far from traditional sources of flooding, can take up to 30 days to appear after a surface water flooding event, and can often last much longer.  All of these factors make groundwater flooding harder to predict and harder to manage.

Refines your existing view of flood risk

By integrating GeoSmart’s Groundwater Flood Risk Map (GW5) into your flood risk data portfolio you can get a more detailed understanding of flood risk from all sources down to property level.

GW5 corresponds to Ambiental’s flood risk model (UKFloodMap4™) in terms of resolution, precision modelling, quality, and a commitment to continually updating and validating their data against actual groundwater flood events.

The highest resolution groundwater flood risk data available

GW5 is the only available groundwater flood risk dataset for Great Britain that shows groundwater risk at 5m resolution. Combining comprehensive data on geology, permeability and historic groundwater levels, it gives you unique insight into the risk of groundwater flooding rather than just susceptibility.

Flexible licensing

GeoSmart GW5 is available with highly flexible licensing options, including regional scale pricing. It can be licensed on its own or integrated with FloodScore™ of UKFloodMap4™.

Test GeoSmart GW5 data for yourself

For a free sample of GeoSmart GW5 data to test against your existing data sources, please contact: Mark Nunns 0203 857 8545 or

ambiental hh zoomed
ambiental GW map image 1

Above is an example of a GW5 groundwater flood risk map of Hemel Hempstead. The advanced resolution is achieved using a 5m horizontal grid resolution which clearly identifies the individual properties at risk. The GW5 data provides information on different groundwater flood risk classification zones as seen by the colouration on the map.

GeoSmart GW5 Technical Details


Great Britain

Modelled Return Periods

1 in 100 years

Horizontal grid resolution

Topography Input Data

Environment Agency 2014/15 LiDAR and Ordinance Survey Terrain 50 (5m DTM)

Update Frequency

Annual/after major events


Regularly validated and calibrated against actual flood events in the UK

Delivery Formats

  • GIS layers: Shapefiles or Raster (floating point/classified/average annual loss)
  • Integrated with all GIS compatible systems and third party underwriting platforms, including Experian, LexisNexis, Spatial Key and Touchstone
  • Appended to Ordinance Survey AddressBase® property level database
  • Flat file to integrate within customers’ systems
  • Physical/PDF maps
  • Through FloodScore™, Ambiental’s online flood risk assessment platform


  • Flexible licensing depending on requirements
  • Regional scale pricing also available, e.g. South of England
  • Annual subscription and transactional ‘per hit’ pricing models available

CONTACT US for pricing and sample data

For a free sample of GeoSmart GW5 data to test against your existing data sources, please contact:

Mark Nunns 0203 857 8545

Back to Top