The aquifer beneath London is subject to a considerable number of stresses including rising groundwater levels, abstraction sustainability, artificial recharge, saline intrusion, groundwater flooding, and the growth of ground source energy. ESI has recently undertaken two key projects for the Environment Agency to aid the management of these pressures in a sustainable and cost effective manner.
The London aquifer is one of the most densely investigated and data-rich in the UK. Following consolidation and analysis of the available data and a comprehensive literature review, ESI have formulated a detailed conceptual understanding of the key hydrogeological processes which occur within the London Basin aquifer. Using the most-up-to-date interpretation of the geology beneath London, ESI furthered current understanding of geological controls on groundwater flow, most notably faulting and structure within the basin and the influence Chalk stratigraphy on aquifer properties. The robust and quantified conceptual model has formed the basis for the construction of a numerical MODFLOW model of the London Basin aquifer, which is currently under development at ESI. The conceptual and numerical models will aid the Environment Agency manage water resources of the basin, comprising tools which enable sound science-based regulatory decision making.
ESI have also recently developed a coupled groundwater flow-heat transport FEFLOW model of central London, building on recent work undertaken on the ‘Cooling the Tube’ project for London Underground Limited. The primary aim of the model is to provide a tool to aid the Environment Agency effectively manage and make regulatory decisions regarding open-loop ground source energy schemes. A series of models were developed to simulate heat transport under a range of operational scenarios, including ‘worst case’ and a range of more realistic operating conditions.