Modelling of rising groundwater levels in the Chalk aquifer of the London Basin

Abstract The rising groundwater level in the confined chalk aquifer of the Central London Basin syncline has been the subject of study and concern for over a decade. Settlement effects in deep foundations and the flooding of tunnels are seen as the main problems arising from resaturation of the London Clay. The Thames Region of the National Rivers Authority has undertaken to formulate a strategy to monitor and control the rise in groundwater levels. Using a finite element, multi-layer computer model of the London Basin aquifer, various scenarios involving groundwater abstraction have been modelled and analysed up to the year 2040. The objective of the study has been to optimize the location of potential groundwater abstraction points and the quantities pumped to provide the most effective control of regional groundwater levels. The water available is seen as a valuable resource for public water supply in an area where there is a demand deficit. The economics of utilizing this resource are complicated, however, by variations in water quality, the cost of treatment and the availability of lower cost water from other resources in some areas.