Some homes have one company for water and another for wastewater.
Use supplier finderRegional watch
Find the company, then check the right data.
This is a map-style starting point. England and Wales use company-area reporting through Ofwat, EA, NRW, and CCW. Scotland and Northern Ireland have separate public routes, so use the country route cards before choosing a regulator.
Map guide
Use the block map as a simple UK route index.
Some areas have separate water-only and wastewater companies. Pollution and sewerage performance usually sits with the wastewater company. Scotland and Northern Ireland use different public routes from Ofwat and CCW.
Scotland
Scottish Water
Separate public route
Northern Ireland
NI Water
Separate public route
North West
United Utilities
Water + wastewater
North East
Northumbrian
Water + wastewater
Yorkshire
Yorkshire Water
Water + wastewater
NE and mid Wales
Hafren Dyfrdwy
Smaller area
Most of Wales
Dwr Cymru
Water + wastewater
Midlands
Severn Trent
Water + wastewater
East
Anglian
Water + wastewater
London and Thames Valley
Thames
Water + wastewater
Wessex
Wessex Water
Water + wastewater
South East coast
Southern
Water + wastewater
South West
South West Water
Water + wastewater
Water-only areas
Affinity, SES, South East, Portsmouth, South Staffs, Bristol
Wastewater may be separate
What the colours mean
Use this as a visual index, not a verdict. Company performance changes each reporting year, and national complaint routes differ.
Find exact supplierSimple view
Use the map as an index, not a verdict.
Leakage, pollution, drinking water, complaints, and billing use different sources.
See datasetsThey show current source notes, not a final judgement on your bill.
Open company notesUK route check
Start with the right national route.
The complaint and evidence route changes by nation. Use these cards to avoid sending a good case to the wrong body.
Use your bill or the supplier finder to identify water and wastewater companies. For unresolved household complaints, the practical route is company first, then CCW. Ofwat, EA, NRW, and DWI each handle narrower regulatory or environmental issues.
Most homes receive water and sewerage from Scottish Water, with charges normally collected through council tax. Complain to Scottish Water first. Water-quality complaints may then go to DWQR, and other unresolved complaints may go to SPSO. WICS sets charges and regulates the Scottish water industry.
Northern Ireland Water provides water and sewerage services. Complain to NI Water first. If unresolved, the Consumer Council can help. The Utility Regulator is the economic regulator for NI Water.
Show company watch cards
Company watch cards
What to check by company area.
These cards combine current official source notes. They are deliberately cautious: they show where to look, not a final judgement on any household bill.
London and Thames Valley
EA rated Thames Water one star in the 2024 environmental performance assessment. Ofwat says Thames is in turnaround oversight and needs material improvements including leakage and internal sewer flooding.
South East coast
EA rated Southern Water two stars in 2024. Ofwat notes improvements in pollution and leakage from 2023-24 levels, but says long duration interruptions are particularly concerning.
South West
EA rated South West Water two stars and said it performed worst for total sewerage pollution incidents per 10,000km sewer in 2024. CCW also rated South West Water poor on complaint volume and handling metrics.
Yorkshire
EA rated Yorkshire Water two stars in 2024. CCW rated Yorkshire Water poor on complaint volume and handling metrics. Ofwat announced a GBP 40m wastewater enforcement package.
North West
EA rated United Utilities two stars in 2024. Ofwat's performance report shows per-capita consumption improved over 2020-25, but EA listed United Utilities among companies significantly below target for total sewerage pollution incidents.
East of England
EA rated Anglian Water two stars in 2024. Ofwat says Anglian met its adjusted per-capita consumption commitment in 2024-25 but needs improvement on pollution incidents.
Wessex region
EA rated Wessex Water two stars in 2024. Ofwat says Wessex has been strong on treatment works compliance and customer satisfaction, while leakage and pollution incidents still need improvement.
Midlands and parts of Wales
EA rated Severn Trent four stars in 2024 and said it was the only company to consistently achieve four stars in the last six years. Ofwat still expects reduction in pollution incidents.
Most of Wales
Ofwat says Dwr Cymru needs material improvement in several areas, including supply interruptions and leakage. Ofwat's Dwr Cymru decision covered misreported leakage and per-capita consumption data and customer redress.
North East and Mid Wales
Ofwat says Hafren Dyfrdwy has shown consistently strong performance in several areas, including pollution incidents and drinking-water quality, but needs to improve internal sewer flooding.
North East and Essex/Suffolk water services
EA rated Northumbrian two stars in 2024. Ofwat says it has strong performance in multiple areas and ended the period as a top performer in water supply interruptions, but pollution incidents need improvement.
Affinity, Portsmouth, South East, South Staffs, SES, Bristol
Water-only companies do not operate sewerage for those areas. Check drinking-water, interruptions, leakage, bills, and arrears with the water-only company, then check wastewater issues with the separate sewerage company.
What to inspect
Use these official datasets for each area.
Leakage
Use Ofwat's Water Company Performance Report and Discover Water to compare leakage trends and company targets.
Pollution
Use the Environment Agency EPA for England, NRW reports for Wales, and Ofwat wastewater investigation updates.
Drinking water
Use DWI annual reports and the DWI problem route for taste, odour, colour, and water-quality concerns.
Complaints
Use CCW complaint handling reports and company complaint performance pages for household complaint patterns.
Regional watch source links
Water UK supplier finder
Ofwat company contact map
Discover Water dashboard
Ofwat performance 2024-25
EA environmental performance 2024
NRW water reports
Scotland water route
Northern Ireland complaint route
Structured company data
How findings are checked
The map is a guide, not a billing-boundary source.