Groundwater Flooding New Year Update

Fourteen warnings or alerts issued by the Environment Agency relating to groundwater flooding are in place (as of 6 January 2019) and groundwater flood risk is highlighted in the flood guidance statement, issued by the national Flood Forecasting Centre. Groundwater is predicted to rise further, with peak levels usually seen in late January or February. The area of elevated groundwater flood risk is wide-spread including parts Lincolnshire, Yorkshire, Dorset, Wiltshire and Sussex. Areas around Kent and South London are also beginning to show above normal conditions.

Groundwater levels in many areas of England increased rapidly over Christmas due to heavy rainfall. Southern England saw the most amount of rainfall on Boxing Day, with up to 10 mm in some coastal areas. The combination of heavy rain and already exceptionally high groundwater levels led to increased run off contributing to river flooding, and surface water flooding. Impact thresholds were reached for a number of Geosmart forecast boreholes with groundwater flooding occurring at locations across the country, for example.

  • Railway closed between Brighton and Haywards Heath due to flooding of Patcham Tunnel. Heavy rain in an area at risk of groundwater flooding and levels reaching maximum for December at a nearby borehole.
  • A35 and A354 closed in Dorset due to flooding in areas identified as being at risk of groundwater flooding.


In Wiltshire, Sussex, Dorset, Hampshire and Lincolnshire EA groundwater flood warnings and groundwater flood alerts have been given with up to 30 in place at one time. There remain 14 warnings or alerts relating to groundwater flooding in place.

With further rainfall forecast expected in the next couple of weeks, the risk of groundwater flooding remains a pressing issue. The Geosmart Groundwater Forecast provides a map to review the spatial trends in future groundwater levels up to 60 days in the future allowing data driven decisions. The forecast is predicting rises in groundwater levels in the Cotswold Limestone and in Lincolnshire Chalk and Limestone formations. We are also predicting rising levels, well above the average in boreholes across the Wessex and Thames areas around Dorchester, Salisbury, Marlborough, Swindon and Cirencester.

Find out more about how GeoSmart can assist you this Groundwater flooding season here.