Affinity Water supplies drinking water to people in parts of London, eastern and south eastern England
Anglian Water supply water and water recycling services to people in the East of England and Hartlepool
Bournemouth Water supplies drinking water to around half a million people in the Bournemouth area
Bristol Water supplies drinking water for people in the city of Bristol and surrounding areas
Cambridge Water supplies drinking water to people in Cambridge
Dŵr Cymru Welsh Water is a not-for-profit company which supplies drinking water and wastewater services to most of Wales and parts of western England that border Wales
Essex & Suffolk Water provides 1.8 million people in the south with water services, and is part of Northumbrian Water Group.
Northern Ireland Water is the sole provider of water and sewerage services in Northern Ireland
Northumbrian Water provides water and sewerage services in the English counties of Northumberland, Tyne and Wear, Durham and parts of North Yorkshire, and also supplying water as Essex and Suffolk Water
Portsmouth Water provides water supply in the City of Portsmouth, part of East Hampshire and part of West Sussex
Scottish Water delivers water and waste water services for Scotland
SES Water supplies water to east Surrey, West Sussex, west Kent and south London
Severn Trent supplies water across the Midlands and Wales
South East Water supplies drinking water in Kent, Sussex, Surrey, Hampshire and Berkshire
South Staffs Water serve parts of Staffordshire in the West Midlands as well as small areas of surrounding counties in England
South West Water provides drinking water and waste water services throughout Devon and Cornwall and in small areas of Dorset and Somerset
Southern water is responsible for the public wastewater collection and treatment in Hampshire, the Isle of Wight, West Sussex, East Sussex and Kent, and for the public water supply and distribution in approximately half of this area
Thames Water is responsible for the public water supply and waste water treatment in most of Greater London, Luton, the Thames Valley, Surrey, Gloucestershire, north Wiltshire, far west Kent, and some other parts of England
United Utilities manages the regulated water and waste water network in North West England, which includes Cumbria, Greater Manchester, Lancashire, Merseyside, most of Cheshire and a small area of Derbyshire
Veolia water is a water treatment company and part of an international group
Wessex water supply water and sewerage services to an area of South West England including Bristol, most of Dorset, Somerset and Wiltshire and parts of Gloucestershire and Hampshire
Yorkshire Water is a water supply and treatment utility company servicing West Yorkshire, South Yorkshire, the East Riding of Yorkshire, part of North Lincolnshire, most of North Yorkshire and part of Derbyshire, in England
Hafren Dyfrdwy provides water only in Wrexham and parts of Denbighshire and Flintshire and both water and wastewater in northern Powys
Leep Utilities owns and operates regulated and non-regulated multi-utility networks across the UK
Associate Members
Uisce Éireann is a state-owned water utility company in Ireland
Guernsey Water is part of the States of Guernsey Trading Assets
Jersey Water collect, treat and supply water for households and businesses in Jersey
The Thames Tideway Tunnel is a 25 km combined sewer under construction, running mostly under the tidal section (estuary) of the River Thames across Inner London
Independent Water Networks own and operate water and wastewater networks across the UK
Manx Utilities is responsible for providing the Isle of Man with safe, reliable, efficient and economic supplies of electricity, natural gas and clean water; as well as processing wastewater.