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Constituency information: Water companies

This page provides contact information for water companies and other relevant bodies that deal with a range of water-related issues in England and Wales. 

The geographical area covered by water and wastewater companies doesn't always align with the boundaries of constituencies or local authorities. This page aims to help MPs and their staff identify responsible companies and their contact details in order to assist constituents. In some cases, it may be necessary to contact industry regulators, local authorities or other organisations to deal with an issue. Further details on this are provided below the dashboard maps. 

Use the dropdown menu below to select the constituency you are interested in and view which water and wastewater companies serve that area. 

To confirm the water supplier for your postcode, you can use the Water UK online tool. Please note that this tool only looks up the water supplier. The wastewater company may be different. 

Water companies in England and Wales

There are 11 regional water and wastewater companies in England and Wales (companies providing sewerage services) and a further five water-only companies. There are also some specific geographical areas served by small limited companies (new entrants). Some customers receive water and wastewater services from different companies. 

Domestic customers are usually served by their regional supplier; however, in some cases, for example on a new development, the site owner may choose another company to provide the water and wastewater services. More information about this process is available from Ofwat. 

Water companies in England and Wales are regulated by four independent bodies across three areas: 

• Ofwat– The economic regulator for the water sector in England and Wales 

• Drinking Water Inspectorate (DWI) – The drinking water quality regulator for England and Wales 

• Environment Agency and Natural Resources Wales – Environmental regulators 

For more information on how water companies in England and Wales are performing across the three areas visit Discover Water. 

Interactive Dashboard: Water and Sewerage Companies by Constituency

If you would like to access this information in an alternative format please email papers@parliament.uk and we will review your request. 

Who to speak to about water issues

Your water or sewerage company should be able to provide information and resolve issues relating to water supply and wastewater drainage. However, for a number of other water-related incidents or queries you may need to speak to the Environment Agency, your local authority or other independent body. Below are some examples of commonly occurring issues and the appropriate organisation to contact for help in resolving them.

Further reading from the Commons Library

• Economic regulation of the water industry in England and Wales. This briefing provides an overview of the economic regulation of the water industry in England and Wales. It describes the price review process that sets customer bills and water company service targets every 5-years, and it includes a summary of the 2019 price review that followed increasing public scrutiny of the sector. 

• Household flood insurance: Flood Re. This briefing describes how Flood Re helps to manage an affordable market for flood insurance for most householders 

• Sewage (Inland Waters) Bill. This briefing covers the Sewage (Inland Waters) Bill 2019-21, a Private Member's Bill introduced by Phillip Dunne MP.  The Bill would amend the Water Industry Act 1991 and place a duty on water companies to ensure that untreated sewage is not discharged into rivers or other inland water bodies. 

• Sewer Flooding. This briefing provides information on sewer flooding, including why it happens, responsibilities for addressing the problem and information on possible compensation. Information on longer-term approaches to sewer flooding and sewer connections is also included. 

• Water meters: the rights of customers and water companies. This briefing explains the powers that customers and water companies have in opting for charging with water meters. It also provides an overview of the relevant Government policy and legislation. 

• Water quality. This briefing examines water quality in the UK, including EU requirements and potential impacts of Brexit. It sets out some key facts and figures for England, Wales, Scotland and Northern Ireland, explains how water quality is measured and discusses action being taken by the Government to manage and improve water quality. 

• Water: non-household retail competition. This briefing providing an update on the water retail market for non-household customers in England. It includes information on support for business customers during the coronavirus outbreak in each nation. 

• Flood risk management and funding. This briefing gives an overview of flood and coastal risk management in the UK, including which bodies manage risk, current policy on flood risk management, and how flood funding works. 

• Autumn and winter floods, 2019-20. This briefing covers the serious flooding that occurred in the UK during the autumn and winter of 2019 to 2020 

Data sources and calculations

The analysis in the interactive map above is based on geographical boundary data from Ofwat. You can download these shapefiles at the links below. These links provide the most recent version of the boundaries of the regional water companies (v1_5, April 2024) but new inset appointments are being granted every month. You can email mailbox@ofwat.gov.uk if you need information on the most recent inset appointment boundaries. The data is provided under the Open Government Licence. The interactive map above reflects the previous version of the data (v1_4, 2022), meaning that recent inset appointments are not shown. 

• Water supply areas (10.1 MB zip) 

• Sewerage services areas (7.2 MB zip) 

Geographical boundaries for environment agency regions are available from the Department for Environment, Food and Rural Affairs (Defra). 

Please note that in the analysis above we have adapted four company names from the Ofwat boundaries to help reflect names that residents and consumers may be more familiar with: 

• In the Hartlepool Area, Anglian Water is named “Hartlepool Water (part of Anglian Water)” 

• In Essex and Suffolk, Northumbrian Water is named “Essex and Suffolk Water (part of Northumbrian Water)” 

• In the Bournemouth area, South West Water is named “Bournemouth Water (part of South West Water)” 

• In the Cambridge area, South Staffordshire Water is named “Cambridge Water (part of South Staffs Water)” 

• In the Bristol area, South West Water is named “Bristol Water (part of South West Water)”. 

Calculations

For each company/constituency pair, an estimated percentage of properties is shown to approximate how much of the constituency each company covers. This is estimated based on the geographical coordinates of unique property reference numbers in the Office for National Statistics  (ONS) UPRN directory. The percentage of properties doesn’t necessarily match the percentage of the population covered by each company, but it is a better approximation than the percentage of the geographical area covered. 

There are some small intersections of company boundaries and constituencies which do not contain any properties are not listed or mapped.  Intersections containing fewer than 30 properties are listed as “few properties". Some of these very small overlaps may be artefacts arising from small mismatches between GIS boundaries. 

Information about the data

Ofwat’s data was updated in April 2024. The boundaries don’t include information on any premises or installations that are located outside the boundary but included in the area (or vice versa). The boundaries are digitised from legal records by the Water Services Regulation Authority (Ofwat) with support from Ordnance Survey. The digital representation of water companies isn’t a legal record of the boundary. The definitive legal record of areas is set out in the appointments of the water and/or sewerage undertakers. 

Data updates

We aim to update this dashboard when Ofwat provides new data. MPs and their staff can contact the Commons Library with queries about updates.