Include regional water and wastewater company boundaries

[RichardTaylor]

According to the regulator Ofwat water companies should be publishing their boundaries on their websites:

https://www.ofwat.gov.uk/regulated-companies/markets/water-bidding-market/water-resources-market-information/

Parliament has collated the boundaries of water supply areas and sewerage services areas which it uses to present an "Interactive Dashboard: Water and Sewerage Companies by Constituency":

https://commonslibrary.parliament.uk/constituency-information-water-companies/
https://commonslibrary.parliament.uk/constituency-information-water-companies/#datasources

There are special cases, eg. certain new developments.