The review, authored by the agency, titled “Rapid evidence assessment and overview of groundwater flood risk management in England” and published last Friday, aimed to give a comprehensive overview of the current approach to groundwater flooding and found it to be severely lacking.
According to the British Geological Survey, groundwater flooding is: “The emergence of groundwater at the ground surface away from perennial river channels or the rising of groundwater into man-made ground, under conditions where the 'normal' ranges of groundwater level and groundwater flow are exceeded.”
This is mainly caused by heavy rainfall, high river levels, sea level rise and human induced changes such as reduced abstraction. The flooding can also last for “weeks or even months, leading to damage and costs that can be substantially higher than equivalent depth fluvial or coastal flooding”, according to the review.
The review included a “comprehensive literature review, a survey sent to risk management authorities and partner organisations and interviews with stakeholders” and looked at “governance, recording flooding incidents, flood risk assessment, flood forecasting and warning, mitigation action and gaps against the national flood and coastal erosion risk management (FCERM) strategy”.
Finding that “a wide range of parties are involved in groundwater flood risk management, not just the organisations with a statutory responsibility”, the review argues that “interactions between the Environment Agency and Lead Local Flood Authorities (LLFAs), and their interaction with other organisations involved in flood risk management should be reviewed and clarified”.
At present “there is no consistent approach to planning, preparing, responding or recovering from groundwater flooding” from these groups, it said.
The EA also found that confusing local reporting methods are “likely to lead to a general under-reporting of groundwater flooding incidents”, with no national system and “no consistent process for recording groundwater flooding”.
In terms of forecasting floods, the report found that “clearer information regarding where groundwater flood warnings and alerts are provided is needed, and this should be publicly available”.
Worryingly, “the evidence gathered indicated that there are gaps in knowledge, processes and data for managing groundwater flood risk”.
The review identifies 25 “activities” to improve the current approach, but is forthcoming that “this is not a detailed roadmap, so does not provide exact timescales and resource needs”.
Innes Thomson, chief executive of the Association of Drainage Authorities, said: "We welcome the work in this area as the effects of groundwater flooding are increasingly giving cause for concern."
Paul Cobbing, chief executive of the National Flood Forum, said: “The report is timely as groundwater, in its many guises, appears to be increasing in frequency. Because we don’t understand how to deal with it as well as other forms of flooding, people often suffer greatly and with water in their homes for extended periods. We need a comprehensive approach; this report is a good start.”