What is a NAV?
New appointments and variations (NAVs) are limited companies which provide a water and/or sewerage service to customers in an area which was previously provided by the incumbent monopoly provider.
A new appointment is made when a limited company is appointed by Ofwat to provide water and/or sewerage services for a specific geographic area. A new appointee has the same duties and responsibilities as the previous statutory water company.
A variation is where an existing appointed company (an “appointee”) asks Ofwat to vary its appointment so it can extend the areas it provides services to.
A NAV, therefore, involves one company replacing another as the appointee for a specific geographic area.
More information can be found about getting a new appointment or variation.
List of NAVs and further information
A list of NAV appointees and our table of relevant NAV documents and links can be found in the boxes on the left-hand side of this page.
Maps of company boundaries
Ofwat produces a digital representation of the water and sewerage undertaker boundaries as GIS shapefiles. The shapefiles are designed for geospatial analysis only. The definitive legal record of water supply and sewerage services areas remains the maps and other information set out in the appointments of companies as water and/or sewerage undertakers and subsequent area variations.
The maps are currently available as Open Data. They can be downloaded from the House of Commons library website: Constituency information: Water companies.
Scroll down to the section on “Data sources and calculations”.
The GIS shapefiles have been digitised from the legal records by Ofwat with support from Ordnance Survey. They are published under the Open Government Licence.
They were last updated in April 2024 and we no longer provide regular updates.
If you have any questions about the GIS shapefiles, please email us at [email protected].