About this website

The information on this website is based on the British Geological Survey's National Geological Model, a low-resolution, 3D model of the geology of the UK. The information is presented at a national scale and is intended to provide basic information about the distribution of the rock formations and their spatial relationships at the national scale. Information describing the methods that were used to generate the maps and how to use the data is also available. Note that the maps should not be used as the basis for regional- or site-scale assessments or investigations.

The maps and data were created between August 2011 and August 2013 and may be updated in the future when more detailed national scale surface mapping becomes available. The maps were produced as part of a larger project, the iHydrogeology project, co-funded by the Environment Agency (EA) and BGS. Consequently, they only cover England and Wales. It is hoped that the maps will be updated and extended to cover Scotland and Northern Ireland in the future.

About the iHydrogeology project

The data and maps have been produced as part of a project, called iHydrogeology, which was jointly funded by the British Geological Survey and the Environment Agency.

The three aims of the iHydrogeology project have been to:

produce a new National Geological Model (NGM) for England and Wales for use in national water resource assessments
attribute the geological units described in the new NGM with information about basic aquifer characteristics such as the class of aquifer, eg the EA's aquifer designation, and other characteristics such as BGS's permeability index designation
using the new NGM, develop a series of national scale maps illustrating the spatial distribution of the geological units that form the principal aquifers and major shale and clay formations in England and Wales.