1 Flood risk from groundwater: examples from a Chalk catchment in 2 southern England 3 4 A.G. Hughes1, T. Vounaki1, D.W. Peach1, A.M. Ireson2, C.R. Jackson1, A.P. Butler2, J.P. Bloomfield3, 5 J. Finch4 and H.S. Wheater2 6 1 British Geological Survey, Keyworth, Nottinghamshire, UK 7 2 Department of Civil and Environmental Engineering, Imperial College London, London, UK 8 3 British Geological Survey, Wallingford, Oxfordshire, UK 9 4 Centre for Ecology and Hydrology, Wallingford, Oxfordshire, UK 10 11 12 13 14 Correspondence Abstract A.G. Hughes, British Geological Survey, 15 Groundwater flooding has moved up the policy-makers’ agenda as a result of the 16 Keyworth, Nottinghamshire, UK Email:
[email protected] United Kingdom experiencing extensive groundwater flooding in winter 2000/ 17 2001. However, there is a lack of appropriate methods and data to support 18 DOI:10.1111/j.1753-318X.2011.01095.x groundwater flood risk assessment. The implications for flood risk assessment of 19 groundwater flooding are outlined using a study of the Chalk aquifer underlying 20 Key words the Pang and Lambourn catchments in Berkshire, UK. Groundwater flooding in 21 Q2 ’; ’; ’. the Chalk results from the water table reaching the land surface and producing 22 long-duration surface flows (weeks to months), causing significant disruption to 23 transport infrastructure and households. By analyzing existing data with a farmers’ 24 survey, it was found that groundwater flooding consists of a combination of 25 intermittent stream discharge and anomalous springflow. This work shows that 26 there is a significant challenge involved in drawing together data and under- 27 standing of groundwater flooding, which includes vital local knowledge, reason- 28 able risk assessment procedures and deterministic modelling.