Groundwater rebound in urban centres

Schematic representation of the bedrock geology of the London Basin and Chalk groundwater levels. This does not include the overlying superficial deposits (Image: Thames Water © 2007)

Groundwater flooding can occur where there has been a decrease in abstraction from large aquifers underlying major urban centres due to a reduction in industrial activities.

This has allowed depressed groundwater levels to recover causing the risk of flooding to subsurface infrastructure, such as tunnels and the basements of buildings, as well as changes in geotechnical and geochemical properties that could result in settlement and corrosion of deeply founded structures.

Groundwater rebound in UK cities

Groundwater rebound has occurred in some of the UK's major conurbations including London, Birmingham, Nottingham and Liverpool.

In London in the late 1990s a group of stakeholders, including Thames Water, the Environment Agency and London Underground, developed a strategy to address this risk by increasing groundwater abstraction from the confined Chalk aquifer underlying central London by around 50 million litres per day, using this water for public and private supply.

This has resulted in the stabilisation of groundwater levels.