This map shows the locations of large raised reservoirs in England and Wales that are managed and controlled by water companies, based on data extracted from the Environment Agency's public register as at 1 November 2022 and published from Natural Resources Wales's public register on 24 October 2022.
A large raised reservoir is a structure that holds 25,000 cubic metres or more of water above ground level. These reservoirs are regulated by the Environment Agency and Natural Resources Wales under the Reservoirs Act 1975 (as amended).
The information on this map is a subset of information available as open data on my Datadaptive site, in CSV, KMZ and Shapefile formats. I have a another map that shows all large raised reservoirs on the public register.